update_engine: Fix typo in comment

BUG=None
TEST=None

Change-Id: Ied3e106259e87b453cdb12600ea1ab90fb668f55
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/system/update_engine/+/2149850
Tested-by: Andrew Lassalle <andrewlassalle@chromium.org>
Auto-Submit: Andrew Lassalle <andrewlassalle@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Commit-Queue: Amin Hassani <ahassani@chromium.org>
diff --git a/real_system_state.h b/real_system_state.h
index 4712008..807a205 100644
--- a/real_system_state.h
+++ b/real_system_state.h
@@ -144,7 +144,7 @@
   // Interface for dlcservice.
   std::unique_ptr<DlcServiceInterface> dlcservice_;
 
-  // Interface for the clock.
+  // Interface for the bootloader control.
   std::unique_ptr<BootControlInterface> boot_control_;
 
   // Interface for the clock.